The subject matter disclosed herein relates generally to electrical coupling devices. More specifically, the present disclosure relates to partial discharge analysis (PDA) coupling devices that generate a pulse signal and a reference signal.
A partial discharge analyzer is an instrument that is used to measure partial discharge on rotating machines, such as motors and generator stator systems. In one example, the partial discharge analyzer is used to monitor the degradation of the insulation within the generator stator windings.
A PDA coupling device is electrically connected to the machine being monitored by the partial discharge analyzer and the partial discharge analyzer. For example, one end of the PDA coupling device (i.e., the high voltage side) may be connected to the leads of the generator stator windings and the opposite end of the PDA coupling device may be connected to ground. The PDA coupling device generates a pulse signal that is received by the partial discharge analyzer. The partial discharge analyzer analyzes the pulse signal to determine, for example, the degradation of the generator stator windings insulation. In order to perform the analysis of the pulse signal, the partial discharge analyzer utilizes a reference signal. This reference signal is conventionally received from another device connected to the partial discharge analyzer. However, the reference signal is usually not “in phase” with the pulse signal, which makes it difficult for the partial discharge analyzer to analyze the pulse signal. As known in the art, to be “in phase”, two signals must go through the maximum and minimum points at the same time and in the same direction.